As broadcast having High Definition (HD) resolution is extended and served nationwide and worldwide, many users are being accustomed to images having high resolution and high picture quality. Accordingly, a lot of institutes are giving impetus to the development of the next-image device. Furthermore, as there is a growing interest in Ultra High Definition (UHD) having resolution 4 times higher than HDTV along with HDTV, there is a need for technology in which an image having higher resolution and higher picture quality is compressed and processed.
In order to compress an image, inter-prediction technology in which a value of a pixel included in a current picture is predicted from temporally anterior and/or posterior pictures, intra-prediction technology in which a value of a pixel included in a current picture is predicted using information about a pixel included in the current picture, entropy encoding technology in which a short sign is assigned to a symbol having high frequency of appearance and a long sign is assigned to a symbol having low frequency of appearance, etc. can be used.